The SuperPET SP9000, also known as Micro-Mainframe or MMF9000, was developed in conjunction with the Department of Computer Science of the University of Waterloo in Ontario, Canada. It was primarily designed with universities and scientists in mind.

Based on the CBM 8000 series design, The SuperPet has two processors, a standard MOS 6502 like all Pet systems, and a Motorola 6809. It could run all the original C-8000 software as well as modern 6809 based compilers and development tools: C, PASCAL, BASIC, APL, FORTRAN, COBOL, Assembler, etc.

The SuperPet was actually built as a programmer's machine allowing developers to work at home and transfer/exchange their files with a mainframe through a true built-in RS-232 interface. A power-on menu gave access to various language packages and several utilities: RS-232 setup, machine language monitor, text editor and terminal program.

Technically speaking, the 6502 and 6809 processors shared the same address and control lines so both CPUs worked on the same memory area except the Kernel ROM that remains independent of each processor.

Commodore 8000 series owners could upgrade their system and make them SuperPets thanks to an optional upgrade package.